ICS was most prevalent in Civ2, where it was possible to settle CxCxC (city, space, city, space, city) and the game mechanics for calculating commerce and science rewarded that tactic. Only two VC's: Total conquest or space.
In Civ3, they addressed that using several tools:
- Increasing the minimum distance
- Adding corruption and waste, where cities settled far from the capital would be less productive
- Adding an optimal city number (OCN) based on map size; cities founded after reaching the OCN would have more corruption and waste
- Added corruption reducing buildings, that countered some of the effects
They added culture as a means of establishing boundaries of an empire; units could trespass without automatically declaring war. Net result was empires of 20 founded cities, which grew to 80 cities or more after conquering.
In Civ4, they retained the minimum settling distance, but changed the cost equation. Each city added costs to the overall economy, until it grew large enough (pop 3 or 4) so that it was a net benefit. Players who expanded rapidly (using their Civ3 instincts) would usually crash their economies. Corruption and waste replaced by health and happiness; resources were used to keep citizens healthy and happy. Cities which lacked health or happiness became less productive, so road and rail networks were needed to provide resources to far-flung cities. Great people were generated using specialist citizens, providing an incentive to grow some cities larger to run those specialists. Net result was fewer self-founded cities, with more incentive to conquer cities.
Note that both Civ3 and Civ4 had victory conditions which depended on claiming lots of land. Conquest VC = eXterminate the other players, or vassalize them in Civ4. Domination VC = control a large percentage of the land in the world, say, 66%.